The Navy Is Tracking Sea Turtles Released by an Aquarium. Here's Why.

VIRGINIA BEACH -- The green sea turtle Grinch has a reputation for being a little difficult to work with at the Virginia Aquarium & Marine Science Center.

Grinch was brought to the aquarium in November after Chincoteague National Wildlife Refuge rangers found the animal floating and presumed to be cold-stunned.

The aquarium cleared Grinch for release after seven months of rehabilitation, including treatment for pneumonia and a bone infection in the front left flipper, at its Marine Animal Care Center.

But there was one more operation Grinch would have to undergo before returning to the wild at the Oceanfront earlier this month. Workers wiped the rear left portion of the turtle's shell with disinfectant and drilled two small holes through it so an acoustic monitoring tag could be tied to it and held in place with an adhesive that will eventually fall off.

The tag communicates with monitoring stations up and down the East Coast that record data any time a turtle with a monitor swims nearby. But it's not just the aquarium that cares where Grinch goes. The Navy does too.

Warships constantly transit in and out of the mouth of the Chesapeake Bay for training and deployments, and the Navy needs to know where endangered species like Grinch are at what times of year.

"It's all driven by the Marine Mammal Protection Act and Endangered Species Act, and the permits and authorizations we have under those for training and testing activities," said Joel Bell, senior marine resources specialist at Naval Facilities Engineering Command Atlantic.

"So understanding the movements of what species of turtles are out there, what areas they use, learning more about their ecology and habitat uses. Where do they go in the summer when they're feeding in the shallower waters, and how they migrate around."

The research conducted by the aquarium and the Navy ultimately feeds into an environmental impact statement the Navy routinely submits to operate in the Atlantic Ocean along the eastern coast of North America, portions of the Caribbean Sea and the Gulf of Mexico. The most recent version of the statement is publicly available at www.aftteis.com. Public comments on it will be accepted during a July 26 meeting at Nauticus in Norfolk.

Sea turtles tend to be loners, so researchers have to track as many individuals as possible to get a sense of their migratory patterns. The aquarium has deployed eight to 15 satellite tags and 10 to 20 acoustic tags a year since 2013. The Navy has spent more than $628,000 in that time tracking the movements of sea turtles in the lower Chesapeake Bay to determine how its activities might affect the endangered animals.

"We're finding from our loggerhead tracking data that a lot of these animals are spending the winter off of Cape Hatteras and Cape Lookout in another very active training area for the Navy" in North Carolina, said Susan Barco, research coordinator for the aquarium's research and conservation division. "We may be focused on Virginia, but we're learning quite a bit about other areas as well."

The Navy has been tracking the movements of loggerheads, green sea turtles and Kemp's ridley turtles but says it now has enough data on loggerheads and is focusing on the other two species.

The Navy provides funding to the aquarium to place tags on species in which it is interested. In addition to acoustic tags, more expensive satellite tags with antennas that transmit real-time data when a turtle comes up for air are attached to some of the animals.

Data from satellite tags are viewable online at seaturtle.org. That from turtles with acoustic tags can only be viewed when someone travels by boat to a monitoring station and downloads the data, which is shared within the scientific community.

Despite Grinch's reputation, the reptile didn't even flinch as a drill emitting a high-pitched whirring sound bore through its shell while aquarium workers held it. Grinch struck a "Superman" pose with all four flippers extended in a sign of stress that accompanies being held out of the water. But aquarium workers said there was little indication the 10-minute procedure to attach the monitor bothered it.

Barco said there's not much in the shell where the holes are drilled that would harm the turtle. The small tags also are located to be as unobtrusive and create as little drag as possible, she added.

"Certainly, they should have some awareness that there's something there. These tags today are no larger than a barnacle and, because of the way we put them on, probably produce less drag than a barnacle," she said.

The tags themselves should fall off within a year or two, which is about how long the batteries in them last. In some cases, the shell will extend over time and push the tags off.

Hundreds of onlookers gathered on the Oceanfront near Neptune Park when the aquarium released Grinch and a few other rehabilitated turtles. They used their fins to crawl beneath a cloudy sky into the murky ocean and quickly disappeared beneath the surface.